U.S. Pat. No. 4,385,088 to Baskin, herein incorporated by reference, discloses an artificial decorative rock of foamed synthetic plastic having a body with an outer surface resembling the concavities and convexities of a natural rock. The outer surface is coated with a strengthening layer of epoxy resin filled with hard sand-like particles which give the outer surface a rock simulating, grained texture. The process involves sculpting a solid, rectangular block of expanded polystyrene into a form resembling a roughly shaped or contoured rock using simple cutting and scraping hand tools, such as knives, scrapers, or heated tools. A hollow is formed inside the rock-like exterior. A liquid epoxy resin, hard particles and preferably dark brown, grey and other rock-like pigments are sprayed on the sculptured form in order to strengthen it and aid in the appearance of a natural stone.
U.S. Pat. No. 5,543,185 to Arete Climbing Systems, Inc., herein incorporated by reference, describes a climbing structure based on the use of polystyrene foam blocks attached to a support structure. The polystyrene is cut to be irregularly shaped like a natural rock giving a more realistic structure. The shaped polystyrene foam is covered with one or more hard coating of a cement-like material applied to the foam to give it strength and to give it a rock-like appearance. The cement-like material consists of a mixture of synthetic fiber strands, acrylic liquid plastic, cement (or plaster), and water. The cement-like material is sprayed on using a hopper or plastering gun and smoothed out using sponges and water. The structure is then buffed to give a final textured structure.
U.S. Pat. Nos. 4,847,026; 4,940,558; 4,960,622; 5,543,185; and U.S. Pat. No. 5,679,189 to Futura Coatings, all of which are herein incorporated by reference, teach a method for producing simulated rocks (or trees) by spraying a high density polyurethane elastomer in a flexible mold. The flexible mold is created by cleaning a native rock with soap and water and then uniformly brushing latex rubber on the exterior. The latex is then reinforced using a fabric and a cradle is produced by spraying the exterior of the mold with two to three pound density polyurethane foam at a thickness of three to four inches. After the preparation of the cradle, the cradle and mold are demolded from the rock model and allowed to cure. During artificial rock manufacture, urethane spraying of the interior of the cradle and mold is carried out employing heated plural component equipment for delivering an isocyanate side and polyol side to the spray gun in an exact ratio.
It is an object of this invention to at least provide a process of modifying environmentally-friendly polymer foams to make them harden and seem like stone in appearance and strength for either artisanal or industrial purposes. The process of hardening the open-cell or closed-cell e-polymer foams with a resin, while in the making, can include the addition of certain chemicals, gases and applied heat and pressure factors that allows the material to reach heightened properties of mechanical performance, insulation capacities and durability, thus acquiring the physical characteristics of natural rock, whilst being in counterpoint lightweight and offering accrued versatility in production techniques, usage applications and handling by the end user.